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Exp Brain Res (2010) 201:421428 DOI 10.1007/s00221-009-2049-1
RESEARCH ARTICLE
Inuence of accuracy constraints on bimanual coordination during a goal-directed task in children with hemiplegic cerebral palsy
Ya-Ching Hung Jeanne Charles Andrew M. Gordon
Received: 17 March 2009 / Accepted: 7 October 2009 / Published online: 23 October 2009 Springer-Verlag 2009
Abstract Previously we found that children with hemiplegic cerebral palsy (CP) have impaired bimanual coordination compared to typically developing children during a functional drawer-opening task. However, performance of the task under time constraints (fast-as-possible) facilitated better bimanual coordination for these children. Accuracy is another important task constraint that could inuence the coordination of the two hands during such tasks. The effect of accuracy constraints on bimanual coordination in children with hemiplegic CP is not well understood. In the present study, children were asked to reach forward and open a drawer with one hand and then activate a light switch inside the drawer with the contra-lateral hand. Task accuracy constraints (different handles and switch sizes) were manipulated in order to determine their effect on upper extremity coordination. Eleven children with hemiplegic CP (age 816 years) and eleven age-matched typically developing children participated in this study. The results show that higher accuracy constraints prolong the total movement completion time for both groups of children. However, children with hemiplegic CP
demonstrated less sequential movement with a higher accuracy constraint (a smaller knob handle) than a lower accuracy constraint (a larger loop handle). Nevertheless, presentation of both higher accuracy constraints (handle and switch) at the same time was detrimental to their performance. These inuences of task constraints were similar regardless of which hand was used to open the drawer. The results suggest that performance may not be linearly related to the constraints, and in some cases more is not better.
Introduction
Children with hemiplegic cerebral palsy (CP) have early non-progressive lesions of the developing brain that result in a number of impairments predominantly on one side of the body. The associated unimanual movement decits of the involved hand have been documented extensively (e.g., Twitchell 1958; Brown et al. 1989; Eliasson et al. 1991, 1992, 1995; Steenbergen et al. 1998; Forssberg et al. 1999; Gordon et al. 1991, 1999, 2003; Gordon and Duff 1999a, b; Wright et al. 2001). However,...